Adding value to vegetable waste: Oil press cakes as substrates for microbial decalactone production

Abstract

In this study several oil press cakes were investigated as exclusive substrates for different moulds and yeasts for the production of flavor-active decalactones via solidstate fermentation (SSF). Experiments are focused on pre-treatment methods for olive cake to remove antimicrobial phenolic substances contained in the oil cake disturbing or even inhibiting microbial growth. Choosing Ceratocystis moniliformis as the reference microorganism best results were obtained by a combination of hot water flushes and enzymatic treatment of the cake. Fermentation with sunflower, olive and linseed cake did not lead to lactone formation in detectable amounts although all of these substrates provided good microbial growth. On castor cake, however, five microorganisms have synthesized the requested decalactones via SSF. Thus fermentation of the fungus Moniliella suaveolens on this substrate resulted in a maximum concentration of g-decalactone of 180.7 mg?kg 21 dry matter without optimization. Another d-lactone, 6-pentyl-a-pyrone, was produced in small amounts by the fungus Trichoderma harzianum on castor cake.

Cellulase Production by Aspergillus japonicus URM5620 Using Waste from Castor Bean (Ricinus communis L.) Under Solid-State Fermentation

“…High activities were obtained using this residue, denoting that this agro-industrial residue is a good substrate for cellulase production by A. japonicus. This substrate contains considerable amounts of valuable substances like sugars, oils, fibers, polyphenols, and cellulose [21], which contribute to the production of cellulases by filamentous fungi.…”

Biotechnology for the production of essential oils, flavours and volatile isolates. A review.

“…Ideally, to keep the cost low and the process economically worthwhile, cheap abundant precursors are sought, able to biotransform into high-value products. The issue of secondary metabolite bioconversions has been developed in several recent reviews [41,78,93,[118][119][120][121][122][123][124][125][126][127] and the discussion here is limited to volatiles only. Some examples are given in Table 4.…”

“…Microorganisms producing volatiles have also been previously cited in several review articles. [93,[118][119][120][121][122][123][124] In most cases the yield of the main compound is <100 mg/l. Far better yields are attained when a substrate biochemically more immediate to the volatile product is used, or when an immediate precursor is included in the culture medium together with the crude substate, a case closer to the biotransformation procedures discussed in the next section.…”

“…Castor oil press cake g-Decalactone,180 mg/kg dry matter [93] Penicillium chrysogenum Hydrolysed maize fibre Vanillic acid 0.81 g/l, vanillin 0.35 g/l, [94] Phlebia radiata (Basidiomycetes) Liquid cultures Bisabolol, aromatic and sesquiterpene alcohols. 2-Methyl-and phenyl-propanol were the main ones at 5 mg/l [95] Piptoporus soliniensis (Basidiomycetes) Liquid media of yeast extract and glucose.…”

Rice Bran or Apple Pomace? Comparative Data Analysis of Astaxanthin Bioproduction

“…Rice bran and apple pomace as two of the most came out of the wastes have been used to produce bio-molecules such as ethyl alcohol, citric acid, microbial colors, enzymes etc. in SSF systems with different type of microorganisms (Laufenberg et al 2004;Joshi & Attri 2006;Gupta et al 2011). Astaxanthin as a red color xanthophyll carotenoid is commercially produced as a targeted bio-molecule and used in preferentially food, feed, aquaculture, nutraceutical, pharmaceutical and poultry areas (Ambati et al 2014).…”